[deliverable/linux.git] / include / linux / namei.h

#ifndef _LINUX_NAMEI_H
#define _LINUX_NAMEI_H

#include <linux/kernel.h>
#include <linux/path.h>
#include <linux/fcntl.h>
#include <linux/errno.h>

enum { MAX_NESTED_LINKS = 8 };

#define MAXSYMLINKS 40

/*
 * Type of the last component on LOOKUP_PARENT
 */
enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT, LAST_BIND};

/*
 * The bitmask for a lookup event:
 *  - follow links at the end
 *  - require a directory
 *  - ending slashes ok even for nonexistent files
 *  - internal "there are more path components" flag
 *  - dentry cache is untrusted; force a real lookup
 *  - suppress terminal automount
 */
#define LOOKUP_FOLLOW		0x0001
#define LOOKUP_DIRECTORY	0x0002
#define LOOKUP_AUTOMOUNT	0x0004

#define LOOKUP_PARENT		0x0010
#define LOOKUP_REVAL		0x0020
#define LOOKUP_RCU		0x0040

/*
 * Intent data
 */
#define LOOKUP_OPEN		0x0100
#define LOOKUP_CREATE		0x0200
#define LOOKUP_EXCL		0x0400
#define LOOKUP_RENAME_TARGET	0x0800

#define LOOKUP_JUMPED		0x1000
#define LOOKUP_ROOT		0x2000
#define LOOKUP_EMPTY		0x4000

extern int user_path_at_empty(int, const char __user *, unsigned, struct path *, int *empty);

static inline int user_path_at(int dfd, const char __user *name, unsigned flags,
		 struct path *path)
{
	return user_path_at_empty(dfd, name, flags, path, NULL);
}

static inline int user_path(const char __user *name, struct path *path)
{
	return user_path_at_empty(AT_FDCWD, name, LOOKUP_FOLLOW, path, NULL);
}

static inline int user_lpath(const char __user *name, struct path *path)
{
	return user_path_at_empty(AT_FDCWD, name, 0, path, NULL);
}

static inline int user_path_dir(const char __user *name, struct path *path)
{
	return user_path_at_empty(AT_FDCWD, name,
				  LOOKUP_FOLLOW | LOOKUP_DIRECTORY, path, NULL);
}

extern int kern_path(const char *, unsigned, struct path *);

extern struct dentry *kern_path_create(int, const char *, struct path *, unsigned int);
extern struct dentry *user_path_create(int, const char __user *, struct path *, unsigned int);
extern void done_path_create(struct path *, struct dentry *);
extern struct dentry *kern_path_locked(const char *, struct path *);
extern int kern_path_mountpoint(int, const char *, struct path *, unsigned int);

extern struct dentry *lookup_one_len(const char *, struct dentry *, int);
extern struct dentry *lookup_one_len_unlocked(const char *, struct dentry *, int);

extern int follow_down_one(struct path *);
extern int follow_down(struct path *);
extern int follow_up(struct path *);

extern struct dentry *lock_rename(struct dentry *, struct dentry *);
extern void unlock_rename(struct dentry *, struct dentry *);

extern void nd_jump_link(struct path *path);

static inline void nd_terminate_link(void *name, size_t len, size_t maxlen)
{
	((char *) name)[min(len, maxlen)] = '\0';
}

/**
 * retry_estale - determine whether the caller should retry an operation
 * @error: the error that would currently be returned
 * @flags: flags being used for next lookup attempt
 *
 * Check to see if the error code was -ESTALE, and then determine whether
 * to retry the call based on whether "flags" already has LOOKUP_REVAL set.
 *
 * Returns true if the caller should try the operation again.
 */
static inline bool
retry_estale(const long error, const unsigned int flags)
{
	return error == -ESTALE && !(flags & LOOKUP_REVAL);
}

#endif /* _LINUX_NAMEI_H */
Commit	Line	Data
	1	#ifndef _LINUX_NAMEI_H
	2	#define _LINUX_NAMEI_H
	3
	4	#include <linux/kernel.h>
	5	#include <linux/path.h>
	6	#include <linux/fcntl.h>
	7	#include <linux/errno.h>
	8
	9	enum { MAX_NESTED_LINKS = 8 };
	10
	11	#define MAXSYMLINKS 40
	12
	13	/*
	14	* Type of the last component on LOOKUP_PARENT
	15	*/
	16	enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT, LAST_BIND};
	17
	18	/*
	19	* The bitmask for a lookup event:
	20	* - follow links at the end
	21	* - require a directory
	22	* - ending slashes ok even for nonexistent files
	23	* - internal "there are more path components" flag
	24	* - dentry cache is untrusted; force a real lookup
	25	* - suppress terminal automount
	26	*/
	27	#define LOOKUP_FOLLOW 0x0001
	28	#define LOOKUP_DIRECTORY 0x0002
	29	#define LOOKUP_AUTOMOUNT 0x0004
	30
	31	#define LOOKUP_PARENT 0x0010
	32	#define LOOKUP_REVAL 0x0020
	33	#define LOOKUP_RCU 0x0040
	34
	35	/*
	36	* Intent data
	37	*/
	38	#define LOOKUP_OPEN 0x0100
	39	#define LOOKUP_CREATE 0x0200
	40	#define LOOKUP_EXCL 0x0400
	41	#define LOOKUP_RENAME_TARGET 0x0800
	42
	43	#define LOOKUP_JUMPED 0x1000
	44	#define LOOKUP_ROOT 0x2000
	45	#define LOOKUP_EMPTY 0x4000
	46
	47	extern int user_path_at_empty(int, const char __user , unsigned, struct path , int *empty);
	48
	49	static inline int user_path_at(int dfd, const char __user *name, unsigned flags,
	50	struct path *path)
	51	{
	52	return user_path_at_empty(dfd, name, flags, path, NULL);
	53	}
	54
	55	static inline int user_path(const char __user name, struct path path)
	56	{
	57	return user_path_at_empty(AT_FDCWD, name, LOOKUP_FOLLOW, path, NULL);
	58	}
	59
	60	static inline int user_lpath(const char __user name, struct path path)
	61	{
	62	return user_path_at_empty(AT_FDCWD, name, 0, path, NULL);
	63	}
	64
	65	static inline int user_path_dir(const char __user name, struct path path)
	66	{
	67	return user_path_at_empty(AT_FDCWD, name,
	68	LOOKUP_FOLLOW \| LOOKUP_DIRECTORY, path, NULL);
	69	}
	70
	71	extern int kern_path(const char , unsigned, struct path );
	72
	73	extern struct dentry kern_path_create(int, const char , struct path *, unsigned int);
	74	extern struct dentry user_path_create(int, const char __user , struct path *, unsigned int);
	75	extern void done_path_create(struct path , struct dentry );
	76	extern struct dentry kern_path_locked(const char , struct path *);
	77	extern int kern_path_mountpoint(int, const char , struct path , unsigned int);
	78
	79	extern struct dentry lookup_one_len(const char , struct dentry *, int);
	80	extern struct dentry lookup_one_len_unlocked(const char , struct dentry *, int);
	81
	82	extern int follow_down_one(struct path *);
	83	extern int follow_down(struct path *);
	84	extern int follow_up(struct path *);
	85
	86	extern struct dentry lock_rename(struct dentry , struct dentry *);
	87	extern void unlock_rename(struct dentry , struct dentry );
	88
	89	extern void nd_jump_link(struct path *path);
	90
	91	static inline void nd_terminate_link(void *name, size_t len, size_t maxlen)
	92	{
	93	((char *) name)[min(len, maxlen)] = '\0';
	94	}
	95
	96	/**
	97	* retry_estale - determine whether the caller should retry an operation
	98	* @error: the error that would currently be returned
	99	* @flags: flags being used for next lookup attempt
	100	*
	101	* Check to see if the error code was -ESTALE, and then determine whether
	102	* to retry the call based on whether "flags" already has LOOKUP_REVAL set.
	103	*
	104	* Returns true if the caller should try the operation again.
	105	*/
	106	static inline bool
	107	retry_estale(const long error, const unsigned int flags)
	108	{
	109	return error == -ESTALE && !(flags & LOOKUP_REVAL);
	110	}
	111
	112	#endif /* _LINUX_NAMEI_H */